Flexible coupling



1953 K. SCHLOTMANN 2,648,958

FLEXIBLE COUPLING Filed Dec. 19, 1949 Patented Aug. 18, 1953 FLEXIBLE COUPLmG Karl Schlotmann, Massen, near Unna, Germany, assignor to Maschinenfabrik Stromag-G. m.

b. H., Unna, Germany Application December 19, 1949, Serial No. 133,729 In Germany December 28, 1948 2 Claims.

This invention refers to flexible couplings for transmitting power from one shaft to another shaft.

One object of this invention is to provide a coupling adapted to be flexed in any direction, which coupling is more wear-resistant and more reliable in operation and has a longer life than the flexible couplings of this type which were known heretofore.

Another object of this invention is to provide a coupling comprising a torsion member of vulcanized rubber or similarly resilient material adapted to be flexed in any direction wherein the torsion member is relieved of any stresses except pressure at certain areas used for attachment thereof to the driving and driven member of the coupling.

Another object of this invention is to provide a coupling comprising a torsion member adapted to be flexed in any direction and securely attached to the driving and the driven member of the coupling in such a way as to minimize wear of the torsion member at the region of attachment. v

Another object of this invention is to provide a coupling comprising a torsion member adapted to be flexed in any direction and provided with means affording added strength where the stresses resulting from attaching the torsion member to the driving and the driven member of the coupling tend to be large.

These and other objects and advantages of the .present invention will be more fully apparent from the particular description thereof, in conjunction with the appended drawing which shows, in preferred forms, two structures embodying the invention.

In the drawings:

Fig. 1 is a cross-section of a laminated torsion member consisting mainly of vulcanized rubber and intended for use in the structure of Figs. 3 and 4 as well as in the structure of Figs. and 6;

Fig. 2 is a side elevation of the torsion member of Fig. 1;

Fig. 3 is a side view, partly in vertical section, of a complete flexible coupling;

Fig. 4 is a side elevation of the structure shown in Fig. 3;

Fig. 5 is a side view, partly in vertical section, of a modification of the structure of Fig. 3 including means for transmitting a braking force to one of the pair of shafts which are flexibly coupled, and

Fig. 6 is a side elevation of the structure shown in Fig, 5, as seen from the left of Fig. 5.

Referring now to Fig. 1, the torsion member I shown therein is generally similar to a rubber tire for motor vehicles 1. e. it issubstantially annular in shape and arcuate in cross-section. Torsion member I is formed by a rubber laminate and comprises an insert la of fibrous material, meshed wire or the like, which is sandwiched be;- tween two outer sheets of vulcanized rubber. Torsion member I is provided with reinforced rims lb which project in a direction axially of torsion member I and form integral parts thereof. As clearly shown in Fig. 1 insert l a has edges bent about degrees out of the general plane thereof and extending into rims lb. A circular concentric reinforcementinsert 2 of fibrous ma terial or wire is associated with each rim lb. The torsion member I is preferably provided with a slot 8, as shown in Fig. 2. Slot 8 mayeither be radial or skew.

Referring now to Figs. 3 and 4, shaft 4 supports a flanged coupling element 3 keyed to it by means of key 3a. Shaft 1 supports a flanged coupling element 3 keyed to it by means of key la. The torsion member I which is flexible in any direction couples the two coupling elements 3 and 3'. As clearly shown in Fig. 3 the annular or toroidal torsion member l extends along and overlaps the periphery of coupling elements 3 and 3'. Each coupling element is provided at, or adajacent to, the periphery thereof with a shoulder substantially L-shaped in cross-section for receiving torsion member I. The cross-section of torsion member I is substantially U-shaped and the torsion member encloses between the shank portions lc thereof the peripheral portions of coupling elements 3 and 3. The rims lb of the torsion member project substantially at right angles from the shank portions lc thereof. The structure of Figs. 3 and 4 is further. provided with a pair of clamping rings 6 angular or substantially L-shaped in cross-section clamping torsion member l to coupling elements 3 and 3. The rims lb of torsion member I and the clamping rings 6 provide radially inner clamping zones where torsion member I is subjected to pressure only and is free from any other stresses, in particular the torsional stresses involved in transmitting a .torque from one shaft and coupling element to the other couplin element and shaft. Each clamping ring 6 is secured by a set of screws 5 to coupling elements 3 and 3', respectively, and is provided with a radially inner clamping surface l3 and a concentric, radially outer spaced clamping surface M. The former is adapted to engage and engages the rims or rim portions lb of torsion 3 member I, while the latter is adapted to engage and engages the shank portions I c of torsion member I. Between each radially clamping surface or area I3 and each radially outer clamping surface or area I 4 a circular zone is defined where torsion member I is less compressed by each of said pair of clamping ringsthan at each said clamping area I3 and each said clamping area M.

Stresses involved in the transmission of power between spaced shafts 4 and 'i' are sealed-ofi at" the radially outer clamping zones I 4 and-hence not transmitted to the radially inner clamping zones I3. clamping areas I3 as well as the'radially outer clamping areas are backed-up by coupling elements 3 and 3'. The annular reinforcement inserts 2 are situated in that portion of torsion member I which is subjected to no stresses other than clamping pressure. clamping surface I3 of torsion member I is situated immediately adjacent andis arranged coaxially with respect to the annular or circular reinforcement insert 2. The diameter of the clamping rings 8 is smaller than the largest diameter of torsion member I and the 'latter 'is thus always exposed to view and can hence readily be inspected. Each clamping ring Sis provided with a radially'outer adjusting surface SL The coupling elements 3 and 3' are each provided with a dog It and II, respectively. These 'dogs I0, II' are adapted to engage upon a predetermined relative rotationof shafts l and I and coupling elements 3 and 3 before the limited amount of torsion to which torsion member I may'safely be subjected'has been exceeded. The

maximum angle of permissible relative rotation ofcoupling elements 3 and 3 has been indicated in Fig. 4by the reference sign a. When this angle is reached, dogs I and I I engage, thus providing for positive transmission of power from one shaft-to the other and relieving torsion member I of additional stresses,

The slot 8 in'torsion member I permits'mounting and replacementof the latter with the flanged coupling elements 3 and 3' mounted on and keyed to shafts 4 and i.

In Figs. 5 and 6 the same reference numbers as in Figs. 3 and 4 have been applied to like parts. Therefore Figs. 5 and 6 need to be described only inasmuch as the structure shown therein'differs from the structure shown in Figs; 3and 4. According to Figs. 5 and 6 one of the clamping rings '6- is provided'with a hub I4. I-Iub I4 is mounted on and keyed by means of a key I5 to the coupling element 3. The clamping ring 6' which is provided with the hub IE is also provided with means defining a cylindrical surface I2 adapted to form a brake drum. Because hub I4 is keyed to coupling element 3, screws 5 need but to exert the required clamping pressure for torsion element I but need not to transmit the braking force from surface I2 to shaft 3. It is apparent from Fig. 5 that the cylindrical surface I2 extends in axial direction along only a portion of the width of the flexible torque-transmitting torsion member, thus enabling relatively free access of ambient air to said torsion member.

It will be apparent from the foregoing and particularly from Fig. 2 and the context thereof that the slot 8 in the torsion member i is an important feature since it enables mounting of the torsion member I on the narrowly spaced coupling elements 3, 3 with said coupling elementsin their narrowly spaced positions. It will also be apparent from the foregoing thatthe coupling ele- It will be noted that the radially inner The radially inner ments are provided each with a substantially L-shaped shoulder for receiving the substantially L-shaped cross-section edge portions of the torsion member I. The latter portions project from the above shoulder portions in a direction longitudinally of shafts 4 and i. It is at these projecting' portions If) that the torsionmember I is engaged by the clamping rings 6' and in addition to being engaged by said rings along portions of the surface thereof remote from said edge portions,

It will be understood that by illustrating herein two preferred embodiments of my invention, I donotintend'to limit invention thereto. It

'- will be apparent to those skilled in the art that various changes and modifications may be made Without departing from the spirit of the invention or from the scope of the appended claims.

It'is claimed and desired to secure by Letters Patent:

1. A flexible coupling comprising a pair of spaced shafts, a pair of flanged coupling elements each secured to one of said pair of shafts, each of said pair of coupiing elements having a shoulder at the periphery thereof substantially L-shaped in cross-section, a flexible torsion-mei'n ber coupling said pair of coupling elements; said torsion member comprising a main body'-and '-a pair of internally reinforced edge portionse'ach resting in said shoulder of one of said'pair ofcoupling elements and each projectingat a substan tially right angle from the general'planeof 'sa'id torsion member, and a pair of clamping rings substantially i..-shaped in cross-section securing said torsion member to each of said pair of c'ou' pling elements, each of said pair ofclanipihg rings having a radially inner clamping'sur face engaging one of said pair of edge portions of said torsion member along a first circuIarcIamping area, and each of said pair of clamping rings having a radially outer clamping surface radially spaced from said radially inner clampingsurface and engaging said torsion member along a second clamping area arranged coaxially with respectto said first clamping area, a circular zone where said torsion member is less compressed by each of said pair of clamping rings than at eacli-said first clamping area and each said second clamping area being formed between each" saidfirst clamping area and each said second clamping area.

2. A flexible coupling comprising a pair of spaced shafts, a pair of flanged coupling elements each secured to one of said pair of shafts, aitorsion member flexible in any direction for coupling said coupling elements, said torsion member'con' sisting of a reinforced sheet material substantially in the shape of a toroid' of substantially U-shaped cross-section enclosing between the shank portions thereof the peripheral por ti'ons of said pair of coupling elements, said torsion m'en fber comprising a pair of rims forming integral parts thereof each projecting from but one side of each said shank portions of said torsion mem ber away from the general plane thereof, and a pair of clamping rings substantially L-shaped in cross-section securing said torsion member to each of said pair of coupling elements, each of said pair of clamping rings having a radially inner clamping surface engaging one of said pair of rims of said torsion member along'a first cir'cular clamping area, and each of said pair of clamping rings having a radially outer clamping sur face radially spaced from said radially inner clamping surface and engaging sa'idtorsion mom- 5 ber along a second circular clamping area ar- References Cited in the file of this patent Fanged COaXiaHy respect Said first Clampmg area, each 'sald first clampmg area and each said second clamping area being backed-up by Number N Date one of said pair of coupling elements, a circular 5 1,656,715 Welland 1923 zone whege saidbtorsiorli m emhgr is con;pr1essed to FOREIGN PATENTS a esser egree y eac or sa1 pair 0 c amplng rings than at each said first clamping area and g gx Date 9 each said second clamping area being formed be- 2 1 3 Great Bn am Sept tween each said first clamping area and each said 10 8 France 2 i 1 40 Second clamping area. 643,172 Germany Mar. 30, 1937 Germany May 23, 

